chr17-17222572-G-C

Variant names:

• chr17-17222572-G-C
• rs750394475
• NM_144997.7:c.708C>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_144997.7(FLCN):​c.708C>G​(p.Asn236Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N236S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FLCN NM_144997.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.761
• Publications: 0 publications found

Genes affected

FLCN (HGNC:27310): (folliculin) This gene is located within the Smith-Magenis syndrome region on chromosome 17. Mutations in this gene are associated with Birt-Hogg-Dube syndrome, which is characterized by fibrofolliculomas, renal tumors, lung cysts, and pneumothorax. Alternative splicing of this gene results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

FLCN Gene-Disease associations (from GenCC):

• Birt-Hogg-Dube syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• Birt-Hogg-Dube syndrome 1

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P, Ambry Genetics
• familial spontaneous pneumothorax

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Ambry Genetics
• renal carcinoma

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• colorectal cancer

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000264187 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.28362286).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FLCN	NM_144997.7	c.708C>G	p.Asn236Lys	missense_variant	Exon 7 of 14	ENST00000285071.9	NP_659434.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FLCN	ENST00000285071.9	c.708C>G	p.Asn236Lys	missense_variant	Exon 7 of 14	1	NM_144997.7	ENSP00000285071.4
ENSG00000264187	ENST00000427497.3	n.149-3518C>G		intron_variant	Intron 4 of 11	1		ENSP00000394249.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Birt-Hogg-Dube syndrome Uncertain:1

Jul 14, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine with lysine at codon 236 of the FLCN protein (p.Asn236Lys). The asparagine residue is highly conserved and there is a moderate physicochemical difference between asparagine and lysine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with FLCN-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Benign	-0.013	T
BayesDel_noAF	Benign	-0.26
CADD	Benign	0.044
DANN	Benign	0.93
DEOGEN2	Benign	0.36	T;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.37	N
LIST_S2	Benign	0.80	T;D
M_CAP	Benign	0.075	D
MetaRNN	Benign	0.28	T;T
MetaSVM	Uncertain	0.16	D
MutationAssessor	Benign	0.035	N;N
PhyloP100		-0.76
PrimateAI	Pathogenic	0.87	D
PROVEAN	Benign	0.030	N;N
REVEL	Uncertain	0.39
Sift	Benign	0.20	T;T
Sift4G	Benign	0.24	T;T
Polyphen		0.51	P;D
Vest4		0.73
MutPred		0.34		Gain of methylation at N236 (P = 0.019);Gain of methylation at N236 (P = 0.019);
MVP		0.30
MPC		0.59
ClinPred		0.22	T
GERP RS		-8.9
Varity_R		0.31
gMVP		0.48

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs750394475; hg19: chr17-17125886;